App Development for Smart Devices. Lec #2: Android Tools, Building Applications, and Activities

Transcription

1 App Development for Smart Devices CS 495/595 - Fall 2011 Lec #2: Android Tools, Building Applications, and Activities Tamer Nadeem Dept. of Computer Science

2 Objective Understand Android Tools Setup Android Development Environment Create HelloWorld Application Understand HelloWorld Structure Familiarize with Android Application Types and Components Understand the Role of Android Activity Know how to Build and Run Android Application Introduce Debug and Publish Page 2 Fall 2011 CS 495/595 - App Development for Smart Devices

3 Developing for Android Eclipse Android SDK Android Development Tools (ADT) Android Virtual Devices (AVD) & SDK Manager The Android Emulator Dalvik Debug Monitor Services (DDMS) The Android Debug Bridge (ADB) Page 3 Fall 2011 CS 495/595 - App Development for Smart Devices

4 Eclipse Page 4 Fall 2011 CS 495/595 - App Development for Smart Devices

5 Eclipse Eclipse IDE for Java Developers Open Select "Downloads" Select Eclipse IDE for Java Developers, 122MB Select Windows32 Extract zip file to c:\eclipse Installation Tutorial: avadevelopers/ Test First Development Tutorial: clipse/ Page 5 Fall 2011 CS 495/595 - App Development for Smart Devices

6 Android SDK Check Your Development Computer Supported Operating Systems Windows XP (32-bit), Vista (32- or 64-bit), or Windows 7 (32- or 64-bit) Mac OS X or later (x86 only) Linux (tested on Ubuntu Linux, Lucid Lynx) Supported Development Environments JDK SE bit version (including JRE) Eclipse IDE for Java Developers - Indigo version 32bit version Android Development Tools (ADT) plugin SDK Installation Android SDK starter package installer_r12-windows.zip Android SDK Components Run Android SDK setup From Available packages window, select all items and then click install Page 6 Fall 2011 CS 495/595 - App Development for Smart Devices

7 ADT plugin Start Eclipse, then select Help > Install New Software Click Add, in the top-right corner. In the Add Repository dialog that appears, enter "ADT Plugin" for the Name and the following URL for the Location: Click OK Wait and you should see "Developer Tools" in the Available Software dialog, select the checkbox next to Developer Tools and click Next. In the next window, you'll see a list of the tools to be downloaded. Click Next. Click Finish. Page 7 Fall 2011 CS 495/595 - App Development for Smart Devices

8 Configure ADT plugin Modify your ADT preferences in Eclipse to point to the Android SDK directory: 1) Select Window > Preferences... to open the Preferences panel (Mac OS X: Eclipse > Preferences). 2) Select Android from the left panel. 3) You may see a dialog asking whether you want to send usage statistics to Google. If so, make your choice and click Proceed. You cannot continue with this procedure until you click Proceed. 4) For the SDK Location, locate your downloaded SDK directory. Click Apply, then OK. (Spaces in path causes an error, if you are using Windows64. For example, C:\Program Files(x86)\Android\android-sdk C:\PROGRA~2\Android\android-sdk) Page 8 Fall 2011 CS 495/595 - App Development for Smart Devices

9 Android Emulator Device Page 9 Fall 2011 CS 495/595 - App Development for Smart Devices

10 Android Emulator Hardware Option Characteristic Description Device ram size The amount of physical RAM on the device, in megabytes. Default value is "96". Touch-screen support Whether there is a touch screen or not on the device. Default value is "yes". Trackball support Whether there is a trackball on the device. Default value is "yes". Keyboard support Whether the device has a QWERTY keyboard. Default value is "yes". DPad support Whether the device has DPad keys. Default value is "yes". GSM modem support Whether there is a GSM modem in the device. Default value is "yes". Camera support Whether the device has a camera. Default value is "no". Maximum horizontal camera Default value is "640". pixels Maximum vertical camera pixels Default value is "480". GPS support Whether there is a GPS in the device. Default value is "yes". Battery support Whether the device can run on a battery. Default value is "yes". Accelerometer Whether there is an accelerometer in the device. Default value is "yes". Audio recording support Whether the device can record audio. Default value is "yes". Audio playback support Whether the device can play audio. Default value is "yes". SD Card support Whether the device supports insertion/removal of virtual SD Cards. Default value is "yes". Cache partition support Whether we use a /cache partition on the device. Default value is "yes". Cache partition size Default value is "66MB". Abstracted LCD density Sets the generalized density characteristic used by the AVD's screen. Default value is "160". Trackball support Whether there is a trackball present. Page 10 Fall 2011 CS 495/595 - App Development for Smart Devices

11 Android Emulator Controls Page 11 Fall 2011 CS 495/595 - App Development for Smart Devices

12 Your First Android Project Select File -> New -> Project -> Android -> Android Project and create the Android project right-click the project and select Run As > Android Application Page 12 Fall 2011 CS 495/595 - App Development for Smart Devices

13 Project Structure src/ - Java packages. Each package can have multiple.java files representing different classes. res/layout/ - XML files that specify the layout of each screen. res/values/ - XML files used as references by other files. res/drawable-hdpi/, res/drawable-mdpi/, and res/drawable-ldpi/ - high, medium, and low dots-perinch resolution pictures. res/color, res/menu, res/anim assets/ - additional non-media files. AndroidManifest.xml specifies the project to the Android OS. Auto-generated files (do not modify): gen/ contains auto-generated code. Class R.java generated by Android Asset Packaging Tool (aapt). default.properties contains project settings. Page 13 Fall 2011 CS 495/595 - App Development for Smart Devices

14 Project Structure Page 14 Fall 2011 CS 495/595 - App Development for Smart Devices

15 Resources, Package, Manifest Page 15 Fall 2011 CS 495/595 - App Development for Smart Devices

16 Android Software Stack Page 16 Fall 2011 CS 495/595 - App Development for Smart Devices

17 Application Framework Page 17 Fall 2011 CS 495/595 - App Development for Smart Devices

18 Android Component Model Packaging: APK File (Android Package) > Collection of components > Components share a set of resources Preferences, Database, File space > Components share a Linux process By default, one process per APK > APKs are isolated Communication via Intents or AIDL > Every component has a managed lifecycle Task (what users know as applications) > Collection of related activities > Capable of spanning multiple processes > Associated with its own UI history stack > Processes are started & stopped as needed > Processes may be killed to reclaim resources Page 18 Fall 2011 CS 495/595 - App Development for Smart Devices

19 Android Application Components i) Activity: Activity is a visual screen for interaction of user with the application. Depends upon design, an application may consists of one or more activities ii) Views: The User interface of an Activities is build with widgets. ii) Service: Service do not have a visual interface, it runs in the back ground, like play back music and fetching data from the network. iii) Broadcast Receiver: Broadcast receiver receive broadcast announcements and response to them according to the situation. iv) Content Provider: Content provider is a SQLite database, which supports the sharing and accessing of data among applications. v) Intents: Asynchronous messages which allow the application to request functionality from other services or activities. vi) Others parts are Android widgets/live Folders and Live Wallpapers. Page 19 Fall 2011 CS 495/595 - App Development for Smart Devices

20 Example of Components Interactions Page 20 Fall 2011 CS 495/595 - App Development for Smart Devices

21 Types of Android Applications Foreground Activity: An application that s only useful when it s in the foreground and is effectively suspended when it s not visible. Background Service: An application with limited interaction that, apart from when being configured, spends most of its lifetime hidden. Examples of this include call screening applications or SMS autoresponders. Intermittent Activity: Expects some interactivity but does most of its work in the background. Often these applications will be set up and then run silently, notifying users when appropriate. A common example would be a media player. Widgets: Interactive visual components that users can add to their home screens. Usually used to display information such as battery levels, weather forecasts, or the date and time. Page 21 Fall 2011 CS 495/595 - App Development for Smart Devices

22 Android s Activity An activity is an application component that provides a screen with which users can interact Activity is usually a single screen Implemented as a single class extending Activity Displays user interface controls (views) Reacts on user input / events An application typically consists of several activities Each screen is typically implemented by one activity Each activity can then start another activity (new screen) An activity may return a result to the previous activity "main" activity is presented to the user when launching the application for the first time. Each activity receives callbacks due to a change in its state during its lifecycle whether the system is creating it, stopping it, resuming it, or destroying it. Page 22 Fall 2011 CS 495/595 - App Development for Smart Devices

23 Activity Lifecycle Foreground Lifetime Visible Lifetime Entire Lifetime Page 23 Fall 2011 CS 495/595 - App Development for Smart Devices

24 Activity Lifecycle Page 24 Fall 2011 CS 495/595 - App Development for Smart Devices

25 Utilizing Activity Lifecycle Functions Simple exercise to see the activity lifecycle in action each overridden function is explicit and a Toast command is added to show on screen when the function is entered Run it on an Android device and try various cases: Changing the screen orientation destroys and recreates the activity from scratch. Pressing the Home button pauses the activity, but does not destroy it. Pressing the Application icon might start a new instance of the activity, even if the old one was not destroyed. Letting the screen sleep pauses the activity and the screen awakening resumes it. (This is similar to taking an incoming phone call.) Page 25 Fall 2011 CS 495/595 - App Development for Smart Devices

26 Back Stack Tasks and Activities Multiple Activity Instances Multiple Tasks Page 26 Fall 2011 CS 495/595 - App Development for Smart Devices

27 Notes on Activity Starting Activity: void startactivity (Intent intent) void startactivityforresult (Intent intent, int requestcode) void onactivityresult (int requestcode, int resultcode, Intent data) Shutting Down Activity: void finish () void finishactivity (int requestcode) Saving Activity Status void onsaveinstancestate (Bundle outstate) void onrestoreinstancestate (Bundle savedinstancestate) Activity A starts Activity B: A's onpause() B's oncreate(), onstart(), and onresume() (Activity B now has user focus.) A s onstop(), if A is no longer visible Page 27 Fall 2011 CS 495/595 - App Development for Smart Devices

28 Building Android Project Eclipse outputs an.apk file automatically to the bin folder of the project Contains all information to run the application, such as compiled.dex files, a binary version of AndroidManifest.xml, compiled resources (resources.arsc) and uncompiled resource files. Eclipse automatically builds application, enables debugging and signs the.apk with a debug key, by default. Page 28 Fall 2011 CS 495/595 - App Development for Smart Devices

29 Building Android Project (detailed) Page 29 Fall 2011 CS 495/595 - App Development for Smart Devices

30 Running Running on the emulator To run (or debug) your application, select Run > Run (or Run > Debug) from the Eclipse menu bar. Be certain to create multiple AVDs upon which to test your application. Running on a device Ensure application is debuggable by setting android:debuggable="true" of the<application> element in AndroidManifest.xml. Set up the device to allow installation of non-market applications. On the device, go to Settings > Applications and enable Unknown sources. Enable USB Debugging on the device. On the device, Settings > Applications > Development > USB debugging. For Windows, use Device Manager to install a USB driver for adb. (<androidsdk>\extras\google\usb_driver) Page 30 Fall 2011 CS 495/595 - App Development for Smart Devices

31 Manual Application Installation Manual Installation using adb App Package: <workspace>\<project Name>\bin\<Project Name>.apk Need adb tool located at <sdk>/platform-tools/ Modify Device settings as in Running on a Device In Command Prompt, type: adb [-d -e] install <path>/<file>.apk Manual Uninstall On device, go to Applications Menu ->Settings->Manage Applications. Select the application which you want to Uninistall, and click on the Uninstall button. Page 31 Fall 2011 CS 495/595 - App Development for Smart Devices

32 Debugging The main components that comprise Android debugging environment are: Device or Android Virtual Device Delvik Debug Monitoring Service (DDMS): graphical program that can capture screenshots, gather thread and stack information, spoof incoming calls and SMS messages, and other features. The Android Debug Bridge (ADB): provides various device management capabilities. JDWP debugger: allows you to step through code, view variable values, and pause execution of an application. A JDWP-compliant debugger is already included in Eclipse. Page 32 Fall 2011 CS 495/595 - App Development for Smart Devices

33 DDMS (Window > Open Perspective > Other... > DDMS) Page 33 Fall 2011 CS 495/595 - App Development for Smart Devices

34 Debug (Window > Open Perspective > Debug) Page 34 Fall 2011 CS 495/595 - App Development for Smart Devices

35 Putting Application on Market Signing Your Application with Eclipse To distribute your application, however, you must build your application in release mode and sign the.apk file with your own private key. right-click the project in the Package Explorer and select Android Tools > Export Unsigned Application Package. Then specify the file location for the unsigned.apk. Versioning Your Applications android:versioncode, android:versionname android:minsdkversion, android:targetsdkversion, android:maxsdkversion Preparing to Publish Check the following checklist: Publishing on Android Market Android Market developer registration: Page 35 Fall 2011 CS 495/595 - App Development for Smart Devices

36 Questions? Page 36 Spring 2011 CS 752/852 - Wireless and Mobile Networking

37 Recommended Assignment Have your development environment setup Programming: Hello World Programming: Utilizing lifecycle activities Page 37 Fall 2011 CS 495/595 - App Development for Smart Devices